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Drug Discovery & Development

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Drug Discovery & Development Drug Discovery & Development Neal G. Simon, Ph.D. Professor Department of Biological Sciences Drug Discovery & Development: Bench, Bedside, & Beyond I. Background II. The R&D Landscape III. Innovation and Transformation IV. The Preclinical Development Process V. Case Study: A Novel Antidepressant VI. Ethical Issues: Money, Data, & Politics Disclaimer “Those who have knowledge, don’t predict. Those who predict, don’t have knowledge.” Lao Tzu, 6th Century BC Chinese Poet Serendipity or Good Science: Building Opportunity Hoffman Osterloh I. Background Drug Development Process: Stages US FDA Drug Development Process: Phases Biopharmaceutical Drug Development: Attrition Drug FDA Large Scale Discovery Pre-Clinical Clinical Trials Review Manufacturing / Phase IV Phase I Phase III 20-100 1000-5000 Volunteers Volunteers 10,000 1 FDA Com- 250 Compounds 5 Compounds Approved pounds Drug IND Submitted Submitted NDA Phase II 100-500 Volunteers 5 years 1.5 years 6 years 2 years 2 years Quelle: Burrell Report Biotechnology Industry 2006 II. The Research & Development Landscape New Chemical Entities: R&D Cost Model Discovery: $263/$824 million Development: $632/1054 million Paul et al (2010). Nature Rev Drug Discovery Annual Private & Public R&D Spending Research & Development Spending: Return on Investment Saltzmann (2009). Feeding the Pipeline III. Innovation & Transformation Innovation Models and Transformation Hu et al (2007) Antidepressants: Me Too Drugs 1986 Fluvoxamine (Luvox; Solvay) SSRI 1987 Fluoxetine (Prozac; Lilly) SSRI 1992 Sertraline (Zoloft; Pfizer) SSRI/NRI 1993 Venlafaxine (Effexor; Wyeth) SSRI/NRI 1996 Buproprion (Wellbutrin; Wyeth) SNRI/DRI 2002 Escitalopram (Lexapro; Forrest) SSRI 2004 Duloxetine (Cymbalta; Lilly) SSRI/NRI 2008 Desvenlafaxine (Pristiq; Wyeth/Pfizer) SNRI 2011 Vilazidone (Vybrid; Forest Labs) SSRI/5HT1a Personalized Medicine (sort of) Discovery & Preclinical Development IV. Discovery & Development Preclinical Development Lead Selection and Drug Candidate Preclinical Drug Optimization (iterative) Confirmation Characterization FDA to Submission Regulatory Efficacy Assessment: Does it work? ADME Profiling: How can it be delivered and what does the body do? Toxicology/Safety Pharmacology Assessment: Is it safe? Pharmaceutics: Is the manufacture viable and controllable? Adapted from TetraQ Stage 1: Lead Selection and Optimization Essential Pharmaceutics • Structural Characterization • Impurity Identification • Solubility assessment • Prototype formulation • Stability testing Screening Efficacy Early Toxicology Early ADME • In silico profiling • Off target screen • In vitro models • Develop simple • In vitro cytotoxicity • In vivo models analytical method • Preliminary AMES • Other • Measure membrane • hERG binding permeability • Plasma Stability Adapted from TetraQ Stage 2: Drug Candidate Confirmation Data from Lead Optimization Stage Preliminary CMC “Benchmark” in Preliminary (Chemistry, ADME Profiling Manufacture and vivo Models Toxicology Control) • Optimized • Formulation for analytical • Maximum GLP Toxicology method tolerated dose • Stability testing • In vivo models development (MTD) of active • Validated • Basic pharma- • Repeat Dose ingredient models cokinetics (PK) (non-GLP) • Detailed • Models in other & Oral • Preliminary physicochemical disease areas Bioavailability Cardiovascular characterization • Determine Safety • Impurity metabolism of Pharmacology analysis drug Adapted from TetraQ Stage 3: Preclinical Drug Characteristics Data from Prior Stages Detailed Preclinical Comprehensive GLP Toxicology CMC ADME Package • analytical method • acute study • ICH Stability development • subchronic repeat Testing • Comprehensive dose study • ICH impurity Pharmacokinetics • Genotoxicity analysis • GLP TK Battery •Develop prototype • Comprehensive • Safety clinical formulation identification of Pharmacology metabolites Regulatory Submission to FDA or Presentation to Pharmaceutical Company Adapted from TetraQ V. Case Study: Agomelatine Major Depression: Symptoms Anhedonia Blunted Affect Disturbed Sleep Weight Gain/Weight Loss Compromised Social Interactions The Scream Fear Circuits: Core Components Hippocampus and Amygdala Anterior & Rostral Cingulate Cortex Insular Cortex Edvard Munch, 1893 Shin & Liberzon (2010) Hypothalamic-Pituitary-Adrenal Axis Biological Sciences Hypothalamic-Pituitary-Adrenal Axis Key Considerations Regulatory Peptides . CRF . AVP Feedback Regulation . Glucocorticoids Biorhythm Disturbance . Sleep .Temperature . Cardiac . HPA axis Biological Sciences Major Depression & Biorhythms Alterations in circadian rhythms of behavior, sleep, core temperature and the secretion of cortisol and other hormones Blunted amplitude of daily rhythms and poor responsiveness to environmental entraining stimuli. Circadian desynchronization may also be triggered by disorganization of the suprachiasmatic nucleus Circadian disturbances may be provoked by an abnormal pineal output of melatonin, a key synchronizer of biological rhythms and sleep Depression is associated with an altered diurnal rhythm of melatonin output, including a blunted night time surge Administration of melatonin itself is ineffective in major depression Re-coordination of biological rhythms by recruitment of melatonergic mechanisms may be a therapeutically relevant strategy for improving depressed states. Melatonin, Circadian Rhythms, & Agomelatine Agomelatine: Mechanism of Action Discovery, Development, Characterization, & Approval of Agomelatine Key Pharmacological Observations V. Ethics Neurontin PFIZER LOSES A ROUND OVER MARKETING OF NEURONTIN By BLOOMBERG NEWS A judge in Boston upheld a jury decision that Pfizer illegally promoted Neurontin for unapproved uses. Pfizer said it would appeal. January 29, 2011 EXPERTS CONCLUDE PFIZER MANIPULATED STUDIES By STEPHANIE SAUL The drug maker manipulated the publication of studies to bolster use of its epilepsy drug Neurontin, according to expert witnesses in a lawsuit against the company. Oct 8, 2008 PFIZER TO PAY $430 MILLION OVER PROMOTING DRUG TO DOCTORS By GARDINER HARRIS Pfizer pleads guilty and agrees to pay $430 million to resolve criminal and civil charges that it paid doctors to prescribe epilepsy drug Neurontin to patients with ailments that drug was not federally approved to treat. May 14, 2004 Politics, Medicine, & Responsibility http://www.youtube.com/watch?v=pPZn9mRQlq4 Serendipity or Good Science: Building Opportunity Hoffman Osterhloh Thank you for your time and attention .
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